The below is my translation of the speech which the late President Kaczynski intended to give at the Katyn memorial. I could not find an English translation online, so I thought you may wish to be the first to make one available on the Web.
I tried to retain as much as I could of the syntax and sentence structure, so it may come across a little odd in parts (remember that Polish is not in the same language group as English). The concluding exclamations were difficult for me to translate, I tried to find a rough equivalent, but the rough English translation doesn’t convey the same meaning as the original. This is the best I could do. The original is recited here.

I thank Kilroy for this. Here is President Kaczynski’s speech:

Honourable representatives of the families of the Katyn massacre victims:

In April 1940, over 21,000 Polish prisoners of war from NKVD camps were murdered. This crime against humanity was committed by the will of Stalin and under the orders of the highest authorities of the Soviet Union. The alliance between the Third Reich and the USSR, the Ribbentrop-Molotov pact, and the aggression against Poland on 17 September 1939 dramatically culminated in the Katyn crime. Not only in the forests of Katyn, but also in Kalinin, Kharkov, and other known and as yet unknown places were the citizens of the Second Republic murdered, citizens who were the basis of our nationhood. At the same time, the families of those murdered and thousands of those living in the “Kresy” [territories subsequently lost to the Soviet Union] were deported into the depths of the Soviet Union, where their untold misery marked the path of the Polish Golgotha of the East.

The most tragic station of this path was Katyn. Polish officers, clergy, administrators, police personnel, border and prison guards were annihilated without trial or sentence. These were the victims of an undeclared war. Their murder was an offense to the laws and conventions of the civilized world. Their dignity as soldiers, Poles and human beings was trampled underfoot. The trenches in which they were buried was to hide their bodies and the truth of the murder. The world was never to know. The families of the dead were robbed of their rights to mourn for their loved ones and remember them. The earth covered the traces of the crime, and the lie was to erase it from the memory of man.

The cover-up of Katyn—a decision of those who commissioned the crime—became one of the fundamental aspects of post war Communist politics in Poland; it was the foundational fraud of the Polish People’s Republic. It was a time during which the memory and the truth of Katyn carried a high price. Nevertheless, those who were close to the victims and other brave people endured with the memory, defended it, and passed it onto future generations. They carried it through the period of Communist rule and preserved it for a free and sovereign Poland. That is why we are indebted to them all, and especially to the families of the victims, and owe them our honour and gratitude. In the name of the Republic, I offer them the deepest and most sincere gratitude, for their defense of this memory of their loved ones, for they have rescued an important dimension of our national consciousness and identity.

Katyn became a painful wound in Polish history, and has for many decades poisoned the relations between Poles and Russians. May this wound fully and finally heal. We are already on this path. We Poles acknowledge and value the actions of Russians of recent years. This path, which is bringing our nations together, we should continue to travel, not halting on the way or retreating back.

All the localities associated with the Katyn crimes must be revealed and investigated. It is important that the innocence of the victims be acknowledged in accordance with the law, and that all documents in relation to this crime be made available. So that the lie about Katyn disappears forever from public discourse. [?] We demand these actions above all else for the memory of the victims and the suffering of their families. But we also demand this in the name of common values, which must form the foundations of trust and partnership between neighbouring nations within all of Europe.

Let us pay our united respects to the murdered victims and pray over their heads. Glory to our heros! For their memory!